Electronic components have become ubiquitous in modern society. The electronics industry proudly, but routinely, announces accelerated clocking speeds and smaller integrated circuit (IC) modules. While the benefits of these devices are myriad, smaller and faster electronic devices create problems. In particular, high clock speeds inherently require fast transitions between signal levels. Fast transitions between signal levels create electromagnetic emissions throughout the electromagnetic spectrum. Such emissions are regulated by the Federal Communications Commission (FCC) and other regulatory agencies. Furthermore, fast speed inherently means higher frequencies. Higher frequencies mean shorter wavelengths. Shorter wavelengths mean shorter conductive elements act as antennas to broadcast these electromagnetic emissions. These electromagnetic emissions radiate from a source and may impinge upon other electronic components. If the signal strength of the emission at the impinged upon electronic component is high enough, the emission may interfere with the operation of the impinged upon electronic component. This phenomenon is sometimes called electromagnetic interference (EMI) or crosstalk. Dealing with EMI and crosstalk is sometimes referred to as electromagnetic compatibility (EMC). Other components, such as transceiver modules, inherently have lots of radiating elements that raise EMI concerns. Thus, even electronic modules that do not have high clock speeds may have EMI issues.
One way to reduce EMI is to shield the IC modules that cause EMI or that are sensitive to EMI. Typically the shield is formed from a grounded conductive material that covers the top and at least a portion of the side of one circuit module. When electromagnetic emissions from the circuit module strike the interior surface of the conductive material, the electromagnetic emissions are electrically shorted through the grounded conductive material, thereby reducing emissions. Likewise, when emissions from another radiating element strike the exterior surface of the conductive material, a similar electrical short occurs, and the module does not suffer EMI from other modules.
However, if the shield fully covers the side of the circuit module, there is a high possibility that chemistries used in the shielding process may attack the input/output (I/O) contacts located at the bottom of the IC module. Alternatively, if the shield only partially covers the side of the circuit module, there are potential escape points for the electromagnetic field (EMF), which may result in decreased shield effectiveness. Thus, there is a need for an improved procedure that allows the shield to fully cover the side of the circuit module to effectively deal with EMI concerns, and does not impact the I/O contacts of the circuit module. In addition, cost effectiveness is desired.